Combination Of Evaporation Research Articles

Unsaturated hydraulic property measurements of subtropical anthropogenic (purple) soils in China

AbstractMany anthropogenic soils, often referred to as red bed or purple soils, are distributed in various areas of southern China. Purple soils typically are highly weathered and often lead to natural and engineering hazards because of their relatively poor water retention properties. Knowledge of the unsaturated soil hydraulic properties of purple soils is crucial for their optimal management and various assessment studies. In this work, the hydraulic properties of purple soils from southern China were measured in the laboratory over the full moisture range using a combination of evaporation (HYPROP) and psychrometer (WP4C) approaches. Measured data were analyzed in terms of four different unimodal and bimodal soil hydraulic models. The measurements and analyses showed that bimodality was not overly significant for most samples. The good fit of the Peters–Durner–Iden models furthermore suggested that corner and film flows were important under relative dry conditions. Existing soil pedotransfer functions were found to provide a fairly close match for the slope of water retention curves with the exception of near saturated water contents and the saturated conductivity. To the best of our knowledge, this is the first time that unsaturated hydraulic data of purple soils are provided over the full moisture range.

Investigating the supremacy of PVD S3p deposition over HiPIMS for AlTiN coating

Dry machining of Duplex Stainless Steel 2205 (DSS2205) is a challenging task due to difficulties including high cutting temperatures, work hardening tendency and Built-up Layer (BUL) formation. Moreover, the high demand for DSS stresses improving machining productivity and quality. This study focuses on inspecting the supremacy of the PVD Scalable Pulse Power Plasma (S3p) coating deposition technique, which is rarely used for dry machining DSS, over High Pulse Impulse Magnetron Sputtering (HiPIMS) to deposit AlTiN coatings. A combination of evaporation and sputtering used for S3p dominated over HiPIMS. After a machining length of 6240 mm, the AlTiN (HiPIMS) coatings were unable to sustain the dry machining conditions, exhibiting faster tool wear rates than the AlTiN (S3p) coatings. As a result, AlTiN (S3p) exhibited a tool life of 8840 mm, 1.6 times higher than the AlTiN (HiPIMS) coating. The effect of decreasing tool life at any selected cutting speed was more severe at higher feed rates (0.19 mm/rev). The tool life decreased by 56%, 32% and 23% for the uncoated, AlTiN (HiPIMS) and AlTiN (S3p) tools, respectively. The surface roughness and cutting force were found to decrease by a notable 13% and 10%, respectively, due to the excellent properties of AlTiN (S3p) coatings compared to AlTiN (HiPIMS) coatings.

Solar-driven watersteam/brine production and brine-driven electricity generation by photothermal fabric coupled with osmotic membrane

The combination of solar-driven seawater evaporation and electricity generation has received increasing attention, and the traditional routes are based on the combination of the evaporator with thermogalvanic cells, thermoelectric or hydrovoltaic modules. But these combinations are relatively complex, and solid salt will crystallize during long-term seawater evaporation, limiting their practical applications. To solve the above problems, herein we have proposed a new kind of evaporation/electricity generation device by combining the photothermal fabric hanging-model evaporator and osmotic membrane-based generator. As a model of photothermal fabric, cotton fabric has been dyed with Chinese ink, and then the cotton-carbon fabric has high hydrophilicity and excellent photoabsorption efficiency (97.1%). Subsequently, the cotton-carbon fabric is set in an arc-shaped design between two seawater tanks for the construction of the hanging-model evaporator. Under the illumination of one sun, the evaporation rate of the hanging-model evaporator is as high as 1.94 kg m−2 h−1 without solid-salt accumulation, and the high-concentration brine (Na+ concentration: 1.07 ×105 mg L−1) can drip from the fabric bottom, realizing solar-driven watersteam and brine production with standing stability. Simultaneously, the brine is separated from the original seawater by a commercial cation exchange membrane, and two Ag/AgCl electrodes are used to construct an osmotic generator. It shows a high open voltage of 52 mV and the highest output power density of 116.52 mW m−2. Therefore, the present integration of the hanging-model evaporator and osmotic generator establishes a new path to continuously produce watersteam and brine under the sun and then to confer brine-driven electricity generation.

Kebutuhan Air Irigasi pada D.I Krueng Pasee Aceh Utara

Water demand is the amount of water volume that must be met for irrigation, in the Krueng Pasee irrigation area of North Aceh has an irrigation network area of 5579 Ha. The purpose ofthis research is to obtain the maximum and minimum irrigation water demand discharge in the study area. This research can be an additional source of knowledge for writers in particular and for readers in general. As well as the results of this study can be known the value of rice planting water needs. The data used in the research is rainfall data sourced from BMKG (Meteorology, Climatology, and Geophysics Agency) Malikussaleh, used to calculate effective rainfall and climate data sourced from BMKGMalikussaleh in the form of temperature data, solar irradiation data, wind speed data and humidity or temperature data used to calculate evapotranspiration (ETo). ETo is a combination of evaporation and transpiration which is defined as the event of water loss from plant tissue and the surface of the soil usedas a place to grow plants. In analyzing ETo using the Penman Modification Methodology. The Penman method by adjusting the wind function according to local conditions produces the best approach to the evapotranspiration rate of the lysimeter results. The consumptive use of plants (ETc) during the land preparation period uses the results of the calculation of water requirements for land preparation (IR). Crop consumptive use (ETc) after land preparation is a calculation between evapotranspiration and cropcoefficient. The calculated irrigation water requirement (NFR) results in water requirement in the form of mm/day. Irrigation water requirements are converted to l/dt/ha with a conversion rate of 1/8.64. The smallest water demand calculation discharge was obtained in November-1 at Q = 4.32 m3/det and thelargest water demand in February -1 at Q = 13.40 m3/det. At the research location, rice planting begins in January-I, with a rice-soybean planting pattern. From the calculation of water demand, Krueng Pasee Irrigation Area has the smallest water demand in November-1 and the largest water demand in February-1.

Modeling hypersalinity caused by evaporation and surface–subsurface exchange in a coastal marsh

A coupled surface water and variably-saturated groundwater model is developed for a coastal salt marsh (Nueces Delta, Texas USA). To evaluate the relative impacts of common model simplifications, the new model is compared against a prior salinity transport model that neglects evaporation and groundwater coupling. Both marsh-scale (at coarse grid resolution) and bank-scale (at fine grid resolution) simulations are used to examine the flux mechanisms in the intertidal zone where soil-moisture evaporation and groundwater fluxes contribute to hypersalinity. New numerical methods provide the groundwater–surface water coupling mechanisms necessary for practical marsh-scale simulations using the two-dimensional (2D) Shallow Water Equations for surface water and the density-dependent 3D Richards equation for groundwater. An asynchronous surface–subsurface coupling scheme is shown to significantly reduce the computational cost of marsh-scale simulations. Comparison of marsh-scale and bank-scale results indicates that a coarse model grid can represent the mechanisms of surface/subsurface salinity flux in the intertidal zone, but likely misrepresents the inundation effects of topography smaller than the model grid. Due to relatively weak tidal amplitudes at the study site, surface-water evaporation is a stronger driver of hypersalinity than surface–subsurface exchange induced by soil-moisture evaporation. The combination of evaporation and groundwater exchange creates small hypersalinity “hot spots” that do not appear in the simulations neglecting these processes. However, including these processes has only a marginal impact on comparisons with field data previously collected in the marsh. Both types of simulations have good agreement for surface-water volumetric transport (as evidenced by water surface levels), but the remaining model-field disagreement in salinity appears to be dominated by biases in salinity transport for oscillatory (tidal, wind-driven) fluxes through narrow channels.

Obtaining potassium sulphate by conversion of potassium chloride and ammonium sulphate

This study investigates the synthesis of potassium sulfate through the conversion of potassium chloride and ammonium sulfate, showcasing the viability of this process. Through systematic experimentation, optimal conditions and the stoichiometric ratio of starting components are determined. The study reveals that in an aquatic environment, the utilization of NH4 + ions reaches an impressive 94-95%. The isolation of potassium sulfate from the liquid phase is achieved through a combination of evaporation and subsequent crystallization. The resulting product is characterized through various analytical methods, offering valuable insights into its composition and potential applications. This research contributes to the advancement of sustainable potassium sulfate production methodologies with implications for agricultural and industrial sectors.

Measurement of Water Absorption of Recycled Aggregate.

Owing to the high absorption capacity of recycled aggregate (RA), it is crucial to accurately measure its saturated-surface-dried water absorption (WSSD), which largely affects an effective water-to-binder ratio of recycled aggregate concrete. In this study, existing measurement methods for the WSSD of RA are extensively reviewed, including Wiping, Slumping, Centrifugation, Infrared, Evaporation, Airflow drying, Conductivity, Pycnometer, Hydrostatic balance, and Extrapolation. In particular, the physical principles and operability of these methods are emphasized. It was determined that the accuracy of all test results was not satisfactory. For example, the water in pores with an open-ended direction that was opposite to the centrifugal force could largely be retained. In Airflow drying, the temperature change was significantly delayed. In addition, in Hydrostatic balance, RA would pre-absorb water before determining the initial reading. Therefore, several suggestions for optimizing these methods are presented, such as the combination of Evaporation and Airflow drying, the liquid selection in Hydrostatic balance, and the addition of a tiny mixer in each centrifuge tube. In summary, this review facilitates the development of an accurate and convenient method for measuring the WSSD of RA.

The effect of relative air humidity on the evaporation timescales of a human sneeze.

The present paper investigates droplet and aerosol emission from the human respiratory function by numerical and experimental methods, which is analyzed at the worst-case scenario, a violent sneeze without a face covering. The research findings develop the understanding of airborne disease transmission relevant to COVID-19, its recent variants, and other airborne pathogens. A human sneeze is studied using a multiphase Computational Fluid Dynamics (CFD) model using detached eddy simulation coupled to the emission of droplets that break up, evaporate, and disperse. The model provides one of the first experimental benchmarks of CFD predictions of a human sneeze event. The experiments optically capture aerosols and droplets and are processed to provide spatiotemporal data to validate the CFD model. Under the context of large random uncertainty, the studies indicate the reasonable correlation of CFD prediction with experimental measurements using velocity profiles and exposure levels, indicating that the model captures the salient details relevant to pathogen dispersion. Second, the CFD model was extended to study the effect of relative humidity with respect to the Wells curve, providing additional insight into the complexities of evaporation and sedimentation characteristics in the context of turbulent and elevated humidity conditions associated with the sneeze. The CFD results indicated correlation with the Wells curve with additional insight into features, leading to non-conservative aspects associated with increased suspension time. These factors are found to be associated with the combination of evaporation and fluid-structure-induced suspension. This effect is studied for various ambient air humidity levels and peaks for lower humidity levels, indicating that the Wells curve may need a buffer in dry climates. Specifically, we find that the increased risk in dry climates may be up to 50% higher than would be predicted using the underlying assumptions in Wells’ model.

Lattice Boltzmann Modeling of Drying of Porous Media Considering Contact Angle Hysteresis

Drying of porous media is governed by a combination of evaporation and movement of the liquid phase within the porous structure. Contact angle hysteresis induced by surface roughness is shown to influence multi-phase flows, such as contact line motion of droplet, phase distribution during drainage and coffee ring formed after droplet drying in constant contact radius mode. However, the influence of contact angle hysteresis on liquid drying in porous media is still an unanswered question. Lattice Boltzmann model (LBM) is an advanced numerical approach increasingly used to study phase change problems including drying. In this paper, based on a geometric formulation scheme to prescribe contact angle, we implement a contact angle hysteresis model within the framework of a two-phase pseudopotential LBM. The capability and accuracy of prescribing and automatically measuring contact angles over a large range are tested and validated by simulating droplets sitting on flat and curved surfaces. Afterward, the proposed contact angle hysteresis model is validated by modeling droplet drying on flat and curved surfaces. Then, drying of two connected capillary tubes is studied, considering the influence of different contact angle hysteresis ranges on drying dynamics. Finally, the model is applied to study drying of a dual-porosity porous medium, where phase distribution and drying rate are compared with and without contact angle hysteresis. The proposed model is shown to be capable of dealing with different contact angle hysteresis ranges accurately and of capturing the physical mechanisms during drying in different porous media including flat and curved geometries.

Chemical evolution of an inland sabkha: a case study from Sabkha Matti, Saudi Arabia

Sabkha Matti is a potential discharge point for regional groundwater systems in the Rub’ al Khali topographic basin of Saudi Arabia. The hydrogeochemical evolution of this sabkha (salt flat) and the underlying aquifers were assessed by using a combination of geological, hydraulic, hydrochemical, and isotopic approaches. A compilation of the geologic structure and lithology in combination with boron isotope data attributed the origin of salinity in the regional aquifers underlying Sabkha Matti to the entrapment of ancient seawater in a coastal lagoon environment during the depositional time of the late Oligocene-Miocene formations. Major ionic constituents and strontium isotope ratios from the trapped paleo-seawater were observed to resemble those obtained from the near-surface sabkha brine. These data, along with hydrostatic head measurements, suggest that the origin of the solutes in Sabkha Matti is associated with brines ascending from the underlying formations. The data also show that solute concentrations in Sabkha Matti are increasing over time through a combination of evaporation, mineral dissolution by recharge, and a density-driven convection mechanism that circulates the solutes. On the other hand, stable isotopes of water (δ18O, δ2H) and radio isotope data (14C and 3H) suggest that the existing waters in the sabkha and the underlying aquifers are relatively recent and were recharged during the wet phase in the late Pleistocene-Holocene between 3,200 and 14,000 BP. This study shows that the water and solutes in Sabkha Matti area are a combination from different sources.

Ongoing anthropogenic eutrophication of the catchment area threatens the Doñana World Heritage Site (South-west Spain)

Eutrophication is a major cause of wetland degradation worldwide. In recent decades, reductions in nutrient inputs have led to improvements in water quality in many rivers and lakes in central and northern Europe, but long-term trends are less clear in southern Europe. We conducted the first comprehensive study of water quality in Doñana (SW Spain), one of the most important wetland complexes in Europe and the Mediterranean region. The core area of Doñana is a large shallow, seasonal marsh (UNESCO World Heritage Site—WHS) that floods during rainy, cool winter months, then dries out during the summer. The marsh is fed by three main streams whose catchments are within a Biosphere Reserve but are impacted by greenhouses (for cultivating fruit, irrigated with groundwater), poorly treated urban wastewaters and tourism. From 2013 to 2016, we monitored nutrient (Total P, Total N, PO4−3, NH4+, NO3−, NO2−) and phytoplankton chlorophyll-a (chla) concentrations in surface waters of the Doñana marsh and the three main streams. We quantified changes in greenhouse cover since 1995 using satellite images. Nutrient concentrations in streams were consistently higher than in the marsh, particularly in the Partido and Rocina streams that regularly reached concentrations equivalent to a “bad physico-chemical status” under the EU Water Framework Directive (WFD), and whose catchments suffered a fivefold expansion of greenhouses from 1995 to 2016. The Partido was the most polluted stream, and the most affected by wastewater effluents, and had particularly high concentrations of NH4+ (Geometric Mean = 0.3 mg L−1) and NO2− (GM = 0.52 mg L−1) across seasons. Patterns in chla concentrations were less consistent, but streams (GM = 6.78 µg L−1) generally had higher concentrations than the marsh (GM = 4.27 µg L−1). Nutrient concentrations in spot samples within the marsh largely depended on a combination of evaporation (as revealed by higher stable isotope δ2H values in the water column) and spatial processes (concentrations increase close to stream entry points, where conductivity is lower). Anthropogenic nutrient pollution in entry streams is a serious problem in Doñana, with extensive stretches too toxic for fish. Reinforcement of policies aimed at reducing nutrient inputs to Doñana are urgently required to meet the biodiversity conservation and environmental objectives for the WHS and WFD, respectively. Paradoxically, the marsh is currently relied upon to purify the water entering from streams.

Modeling dynamics of pressure fluctuations in a microchannel heat exchanger covered with a wire mesh membrane

Pressure and mass flow fluctuations in a system consisting of a microchannel two-phase heat exchanger with wire mesh covering and overflow chamber were modelled by employing mass, momentum, and energy balances on the fluid in mesh volume. These fluctuations are a result of the alternate wetting and drying of the mesh membrane driven by a combination of evaporation and capillary pressure-driven flow into the mesh. Experiments using a system of eleven parallel microchannels, each of dimension 32 x 0.25 x 0.5 mm, slotted into a copper substrate and covered with a stainless steel mesh of 0.025 mm wire and 0.026 mm aperture, confirm the occurrence of these high frequency pressure and mass flow fluctuations. The use of non-linear methods that included attractor reconstruction and recurrence plotting to enhance predictive capabilities is also explored.

Deep Multi-Stage Reference Evapotranspiration Forecasting Model: Multivariate Empirical Mode Decomposition Integrated With the Boruta-Random Forest Algorithm

Evapotranspiration, as a combination of evaporation and transpiration of water vapour, is a primary component of the global hydrological cycle. It accounts for significant losses of soil moisture from the earth to the atmosphere. Thus, reliable methods to monitor and forecast evapotranspiration are required for decision-making in many sectors. Reference evapotranspiration, denoted as ET, is a major parameter that is useful in quantifying soil moisture in a cropping system. This article aims to design a multi-stage deep learning hybrid Long Short-Term Memory (LSTM) predictive model that is coupled with Multivariate Empirical Mode Decomposition (MEMD) and Boruta-Random Forest (Boruta) algorithms to forecast ET in the drought-prone regions (i.e., Gatton, Fordsdale, Cairns) of Queensland, Australia. Daily data extracted from NASA’s Goddard Online Interactive Visualization and Analysis Infrastructure (GIOVANNI) and Scientific Information for Land Owners (SILO) repositories over 2003–2011 are used to build the proposed multi-stage deep learning hybrid model, i.e., MEMD-Boruta-LSTM, and the model’s performance is compared against competitive benchmark models such as hybrid MEMD-Boruta-DNN, MEMD-Boruta-DT, and a standalone LSTM, DNN and DT model. The test MEMD-Boruta-LSTM hybrid model attained the lowest Relative Root Mean Square Error (≤ 17%), Absolute Percentage Bias (≤ 12.5%) and the highest Kling-Gupta Efficiency (≥ 0.89) relative to benchmark models for all study sites. The proposed multi-stage deep hybrid MEMD-Boruta-LSTM model also outperformed all other benchmark models in terms of predictive efficacy, demonstrating its usefulness in the forecasting of the daily ET dataset. This MEMD-Boruta-LSTM hybrid model could therefore be employed in practical environments such as irrigation management systems to estimate evapotranspiration or to forecast ET.

Development, distribution and palaeoenvironmental significance of terrestrial carbonates in the Petra region, southern Jordan

Terrestrial carbonate deposits are common in both natural and human-modified landscapes in Petra and its surroundings.Three broad genetic categories are recognized: cementations of pre-existing clastics (veins, crusts, cemented cobbles); free-water deposits (Massive Laminated Deposits (MLD), rhizoliths, carbonate blisters, coatings on archaeological water delivery systems), and pedogenic deposits (nodules, calcrete).The oxygen isotopic composition of carbonates suggests mainly precipitation from stored water that reflects the weighted isotopic average of rainfall in the area. Oxygen and carbon isotope data indicate that a combination of evaporation and CO2 degassing are the mechanisms for precipitation, depending on the setting and climate at the time of deposition. Strontium isotopes of carbonates point to an aeolian source (from adjacent sources) for the calcium. The cementations of pre-existing clasts are both markers of previous base levels in the case of cemented cobbles, and the presence of soil above impermeable bedrock in the case of crusts and veins. These types of deposits help to discover previously terraced sites.The open water deposits reflect humid Pleistocene conditions, and their presence inform on the extent and distribution of water resources that may have been available in the Late Pleistocene and early Holocene.

Evapotranspiration Models: Short Review

The evapotranspiration (ET) is a combination of evaporation and transpiration. Where the water is lost from the soil surface and from the crop canopy. The evaporation (E) and transpiration (T) occur instantaneously with no distinguishing between theme. During bare soil stage the E is the dominant process while the T is the effective one when the crop coverage is 100%. The ET is affected with weather conditions, crop features, management and environmental features. The ET methods varied based on the complexity of the model. The air temperature (Ta) is the most critical driving factor which has been used in all ET estimation models. Solar radiation (Ra) intensity and period have been involved in most models. Relative humidity (RH) and wind speed (U) are important parameters affecting on vapor pressure deficit (VPD). The VPD gradient is the most limiting factor affecting the ET rate. Remote sensing is a promising technology. It is prepared to be instead of traditional technologies in the future. The NDVI is a good physical indicator for earth’s land cover classes. The surface temperature results are related to the substance’s potential energy. Scientists still search out to find a way of using remote sensing as a stand-alone technology. A short review on ET models and its new trends are the main target of this work.

Water Balance Evaluation of Chandigarh Region, India.

The water balance is an accounting of the inputs and outputs of water. The water balance of a place, whether it is an agricultural field, watershed, or continent, can be determined by calculating the input, output, and storage changes of water at the Earth's surface. The assessment also takes into account the existing supply of stocks and future appropriation of these stocks. Water inputs are brought by precipitation. Outputs are from the combination of evaporation and the transpiration of plants, called evapotranspiration. Both quantities are estimated in terms of the amount of water per surface unit, but they are generally translated into water heights, the most currently used unit being the millimeter. Usually, the planning and implementation of water use is undertaken in silos with little or no interaction between and across sectors. This leads to frequent water scarcity and water pollution. About 30% of people in India live in cities that are expected to double in population by 2050. With a growing economy and changing lifestyles the pressure on already strained water resources is increasing. The government has shown an interest in Integrated Urban Water Management (IUWM) as a new framework and approach for thenation.

A combination of evaporation and chemical preservation for long‐term storage of fresh sweet sorghum juice and subsequent bioethanol production

Evaporation and chemical preservation were combined for long‐term storage of sweet sorghum juice (SSJ). The preserved SSJ was further used as substrate for ethanol fermentation. Different chemicals including hydrogen peroxide, sodium hypochlorite, sodium benzoate, and methyl paraben were used as co‐preservatives and were added into concentrated SSJ that contains ~40% (w/v) of sugars. The effects of chemical preservatives on sugar storage and ethanol fermentation were compared. The results showed that methyl paraben has better sugar preservation ability and an acceptable yeast toxicity when compared with other chemicals. The addition of methyl paraben in concentrated SSJ was further evaluated and optimized. By adding 0.4 g/L of methyl paraben, 95.1% of fermentable sugars in SSJ were preserved after a 90‐day preservation at room temperature. Ethanol concentration of 121.1 ± 4.6 g/L with a yield of 0.45 ± 0.02 g/g was obtained using the preserved SSJ in batch fermentation. PRACTICAL APPLICATIONS: Ethanol production by sugar‐containing juices is of interest because it is more effective, cheaper, and easier than the lignocellulosic routes. However, the commercialization of the bioethanol plants that uses the sweet sorghum juice as a substrate has long suffered from the deterioration of sugars. As a consequence, the ethanol fermentation process is limited by the short intermittent substrate supplementation in order to satisfy the harvest of the fresh stalks. This work comes up with a novel “evaporation+chemical” preservation method. The synergistic effect of high concentration of sugars and methyl paraben preservative showed inspiring sugar preservation results. Most of the sugars in the sweet sorghum juice were preserved for at least 90 days at room temperature and can be used for ethanol fermentation effectively. The continuity of fermentation can be significantly improved, which showed promising results in year‐round operations.

Comparison of Evolutionary Computation and Empirical Penman-Monteith Equation for Daily and Monthly Reference Evapotranspiration Estimation in Tropical Region

Evapotranspiration is the combination of evaporation and transpiration processes that give means the process of water loss to the atmosphere. Reference evapotranspiration (ETo) estimation is part of water cycle that importance for planning and management of irrigation purposes and water resource systems. Due to its importance, the accurate modeling of ETo is of vital importance to estimate crop water requirement and its availability. This research presents a system identification and differential evolution approach by using Differential Evolution and System Identification (DESI) and Modified Genetic Algorithm (MGA) approach for modeling daily and monthly ETo in peninsular of Malaysia. The data set comprising air temperature, humidity, wind speed, and solar radiation was utilized for estimating ETo using FAO56 Penman Monteith (PM) equation as the reference. The modeling results were analyzed and compared with the traditional Penman Monteith method. Based on the analyses, the approach used was found that the models of ETo is adequate and understandable, and suited to estimate the dynamics of the evapotranspiration process. The performance of the model is comparable with that of the PM method.

Temporal dynamic of malaria in a suburban area along the Niger River

BackgroundEven if rainfall and temperature are factors classically associated to malaria, little is known about other meteorological factors, their variability and combinations related to malaria, in association with river height variations. Furthermore, in suburban area, urbanization and growing population density should be assessed in relation to these environmental factors. The aim of this study was to assess the impact of combined environmental, meteorological and hydrological factors on malaria incidence through time in the context of urbanization.MethodsPopulation observational data were prospectively collected. Clinical malaria was defined as the presence of parasites in addition to clinical symptoms. Meteorological and hydrological factors were measured daily. For each factors variation indices were estimated. Urbanization was yearly estimated assessing satellite imaging and field investigations. Principal component analysis was used for dimension reduction and factors combination. Lags between malaria incidences and the main components were assessed by cross-correlation functions. Generalized additive model was used to assess relative impact of different environmental components, taking into account lags, and modelling non-linear relationships. Change-point analysis was used to determine transmission periods within years.ResultsMalaria incidences were dominated by annual periodicity and varied through time without modification of the dynamic, with no impact of the urbanization. The main meteorological factor associated with malaria was a combination of evaporation, humidity and rainfall, with a lag of 3 months. The relationship between combined temperature factors showed a linear impact until reaching high temperatures limiting malaria incidence, with a lag 3.25 months. Height and variation of the river were related to malaria incidence (respectively 6 week lag and no lag).ConclusionsThe study emphasizes no decreasing trend of malaria incidence despite accurate access to care and control strategies in accordance to international recommendations. Furthermore, no decreasing trend was showed despite the urbanization of the area. Malaria transmission remain increase 3 months after the beginning of the dry season. Addition to evaporation versus humidity/rainfall, nonlinear relationship for temperature and river height and variations have to be taken into account when implementing malaria control programmes.

Calcite precipitates in Slovenian bottled waters.

Storage of bottled waters in varying ambient conditions affects its characteristics. Different storage conditions cause changes in the initial chemical composition of bottled water which lead to the occurrence of precipitates with various morphologies. In order to assess the relationship between water composition, storage conditions and precipitate morphology, a study of four brands of Slovenian bottled water stored in PET bottles was carried out. Chemical analyses of the main ions and measurements of the physical properties of water samples were performed before and after storage of water samples at different ambient conditions. SEM/EDS analysis of precipitates was performed after elapsed storage time. The results show that the presence of Mg2+, SO42-, SiO2, Al, Mn and other impurities such as K+, Na+, Ba and Sr in the water controlled precipitate morphology by inhibiting crystal growth and leading to elongated rhombohedral calcite crystal forms which exhibit furrowed surfaces and calcite rosettes. Different storage conditions, however, affected the number of crystallization nuclei and size of calcite crystals. Hollow calcite spheres composed of cleavage rhombohedrons formed in the water with variable storage conditions by a combination of evaporation and precipitation of water droplets during high temperatures or by the bubble templating method.